Controversial Windows Recall AI Search Tool Returns With Proof-of-Presence Encryption, Data Isolation

Three months after pulling previews of the controversial Windows Recall feature due to public backlash, Microsoft says it has completely overhauled the security architecture with proof-of-presence encryption, anti-tampering and DLP checks, and screenshot data managed in secure enclaves outside the main operating system.

The feature, which uses artificial intelligence to create a searchable digital memory of everything ever done on a Windows computer, will also be turned off by default and fitted with tools to delete it forever from the Windows operating system.

The Windows Recall security makeover is meant to quell fears that the technology is a major security and privacy risk because it takes snapshots of a user’s Windows screen every five seconds and stores it locally for AI-powered semantics search.

In an interview with SecurityWeek, Microsoft vice president David Weston said the company’s engineers rewrote the security model of Windows Recall to reduce attack surface on Copilot+ PCs and minimize the risk of malware attackers targeting the screenshot data store.

“We’ve never built anything on the client side this significant,” Weston said of the security and privacy models, security architecture, and technical controls implemented in the new-look Windows Recall. “It’s now fully encrypted, and tied to the user’s physical presence.”

Weston said Recall will now be an “opt-in experience” during setup. “If a user doesn’t proactively choose to turn it on, it will be off, and snapshots will not be taken or saved,” he explained, noting that Windows users can remove the feature entirely.

“You can remove it completely, never be turned on in future,” Weston said. 

Under the hood, the Microsoft VP said snapshots and any associated information in the vector database are always encrypted with keys that are protected by the TPM (Trusted Platform Module), tied to a user’s Windows Hello Enhanced-Sign-in Security identity.

“You have to have proof-of-presence to turn it on,” Weston said. 

He said Recall’s services that handle snapshots and sensitive data will now operate within secure Virtualization-Based Security (VBS) enclaves, ensuring that no information leaves the enclave unless actively requested by the user. 

The revamped Windows Recall security architecture. Source: Microsoft.

Access to Recall’s settings or user interface is controlled by Windows Hello Enhanced Sign-in Security, and actions like changing settings or accessing data require user presence verification via camera or fingerprint sensor.

Weston argues that this design protects against malware and unauthorized access through rate-limiting, anti-hammering measures, and PIN fallback mechanisms. Sensitive data, including screenshots and extracted text, is encrypted and isolated so that even a system administrator cannot access it. 

The system leverages a just-in-time authorization model — similar to password managers — where access is granted temporarily, and all data is removed from memory when the session ends or times out.

Weston said Windows Recall is designed to never save data from in-private browsing sessions and users will have tools to filter out specific apps or websites viewed in supported browsers. Additionally, users can determine how long Recall retains data and limit the amount of disk space allocated to snapshots.

Weston said DLP technology from the Microsoft Purview enterprise product is running in the background to proactively block private information like passwords, national ID numbers, and credit card data from being stored in Recall. 

If users find content in Recall that they didn’t intend to save, Weston said they can easily delete data from a specific time range, remove content from individual apps or websites, or clear all stored information. A system tray icon provides real-time visibility into when snapshots are being saved and allows users to pause the feature at any time.

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